Core Viewpoint - The article discusses the navigation signal anomalies in Nanjing on December 17, 2025, clarifying the technical reasons behind the issue and emphasizing the strategic significance of the Beidou and GPS systems' compatibility [2][5]. Technical Analysis - Offline maps cannot resolve the navigation anomaly as the core issue is the temporary interference of GNSS satellite signals (including Beidou and GPS), not a network signal interruption [3]. - The core function of offline maps is to store geographic data, which only addresses the "map display" issue and cannot replace the positioning signal source [4]. - Mobile navigation relies on GNSS satellite signals (at least 4 satellites) to calculate position coordinates, and the positioning signal and map data are independent systems [4]. - The interference specifically targeted the civilian frequency bands of Beidou and GPS, preventing the positioning signal from being recognized by receivers, leading to issues like positioning drift and lack of data feedback, making effective navigation impossible [4]. Strategic Significance - The simultaneous impact on Beidou and GPS signals during the anomaly validates the forward-looking strategic vision of China's Beidou system's civilian frequency band planning [5]. - The international satellite navigation spectrum resources follow a "first come, first served" rule, with GPS having occupied core L-band resources early on, leaving limited quality spectrum for Beidou [6]. - Under the framework of the International Telecommunication Union, the compatibility of Beidou's civilian signal (B1C band) with GPS's civilian signal (L1C band) breaks the spectrum resource blockade and creates a strategic balance where interference with Beidou also affects GPS [6]. - Given the military ties of the U.S. and EU, NATO systems also rely on GPS signals, making this frequency compatibility a significant strategic deterrent against malicious interference [6]. Military Frequency Resilience - The signal anomaly only affected civilian GNSS frequency bands, while Beidou's military frequency remains unaffected [7]. - Beidou employs a military-civilian frequency separation design, with military frequencies being exclusive and confidential, physically isolated from civilian bands [7]. - The military system incorporates full digital anti-jamming technology and adaptive intelligent filtering algorithms, enabling precise identification and filtering of interference signals, thus possessing strong anti-jamming and anti-deception capabilities [7]. - The independence and anti-jamming capabilities of Beidou's military frequency provide stable and reliable time-space services for national defense security and emergency support in critical areas, unaffected by the civilian signal interference [7].